Comfort humidity indicator

ABSTRACT

A weather instrument including a hygrometer and an outdoor thermometer, an indoor thermometer, and means operatively associated therewith for providing an indication of the relative humidity required to maintain a predetermined temperaturehumidity relationship. In one embodiment, a cam-filament arrangement responds to a manual positioning, in accordance with information derived from integral measuring devices, to automatically provide an indication of the relative humidity required to maintain a predetermined temperature humidity relationship. The deviation between ambient and optimum humidity is ascertained by comparison of the coaxially mounted instruments indicating these two conditions.

Ullitfll States Patent 91 Preis'er et al.

[m 3,709,039 [4 1 Jan.9,1973

[54] COMFORT HUMIDITY INDICATOR [75] inventors: ii alph fi. Freiser; ClarencejaGoodwin, both of Peru; Robert D. Cofoid,

Tonica, Ill.

[73] Assignee: GeneralTimeCorporation,Ehoeiiiit,

Ariz.

[22] Filed: Aug. 31, I971) [211 Appl. No.: 68,072

[52] US. Cl ..73/336, 73/344 [51] Int. Cl. ..G01n 19/10, GOlw 1/04 [58] Field 01 Search .....73/336, 368.7, 344; 235/109, 235/1 12, 113

[5 6] Reterences Cited UNITED STATES PATENTS 2,106,083 1/1938 Chappell ..73/336 1,460,909 7/1923 Joannes..... 1,998,340 4/1935 Streb 2,874,571

2/1959 Hevener ..73/336 Primary Examiner-S. Clement Swisher Assistant Examiner-Denis E. Corr Attainey-Pen'nie, Edmonds, Morton, Taylor and Adams [57] ABSTRACT A weather instrument including a hygrometer and an outdoor thermometer, an indoor thermometer, and

means operatively associated therewith for providing an indication of the relative humidity required to maintain a predetermined temperature-humidity relationship. In one embodiment, a cam-filament arrangement responds to a manual positioning, in accordance with information derived from integral measuring devices, to automatically provide an indication of the relative humidity required to maintain -a predetermined temperature humidity relationship. The deviation between ambient and optimum humidity is ascertained by comparison of the coaxially mounted instrumcnts indicating these two conditions.

7 Claims, 2 Drawing Figures PATENTEDJAH 9 I975 COMFORT HUMIDITY INDICATOR The present invention relates generally to weather instruments and, more particularly, to instruments which indicate the relative humidity required to cor- 2. For outdoor temperatures above '+40F the comfort relative humidity remains a constant 45%. It is a primary object of the present invention to provide an improved instrument which senses the outdoor temperature and, by manual positioning of an indicator to correspond to the sensed outdoor temperature,.

produces an output indicating the humidity condition corresponding to the desired CRH.

An important object of the invention is to provide, by use of co-axially mounted relative humidity indicating means, an instantaneous indication of a discrepancy between optimum and ambient relative humidities.

Another object of the invention is to provide such an instrument which has a high degree of accuracy over relatively wide rangesv of temperature and relative humidities.

Still another object of the invention is to provide such an improved instrument which provides a continuous indication of ambient conditions and outside temperature.

Yet another object of the invention is to provide an instrument of the type described, which can be manufactured simply and rapidly at a low cost, and yet is accurate and reliable over long operating periods. in this connection, a related object is to provide such an instrument which can be efficiently manufactured at high production rates. I

Other objects and advantages of the invention will become apparent upon reading the following detailed description upon reference to the drawings, in which:

FIG. 1 is a front elevation view of the indicating and calculating portion of a weather instrument embodying the present invention. 1

FIG. 2 is a section taken along 22 in FIG. 1.

, While the invention will be described in connection with certain preferred embodiments, it will be understood that it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention.

Turning now to the drawings and referring first to H6. 1, there is illustrated a weather instrument having three different meters for providing separate indications of outdoor temperature, indoor temperature and ambient relative humidity.

The ambient relative humidity indicator 18 associated with a relative humidity scale is mounted on the output shaft 18a of a conventional hygrometer unit 19, which is preferably of the type utilizing a nylon 6 film as its humidity sensing element as' described ina copending R. H. Preiser et al. application Ser. No. 628,166, filed Apr. 3, 1967, entitled Hyg'rometer and assigned to the assignee of the present invention; however, the invention is not limited to this particular hygrometer movement. The relative humidity scale is located on the front of the display panel 20 of the instrument to provide a continuous direct'readin'g of the ambient relative humidity.

The indoor temperature indicator 15, associated with a temperature scale, is mounted on the output shaft l5a of a conventional thermometer unit 14, which is preferably of the type utilizing a bi-metal element 31 as the temperature sensing element. The temperature scale is located on the front of the display panel 20 of the instrument to provide a continuous direct reading of the indoor temperature.

The outdoor thermometer portion of the illustrative instrument includes an indicator 16, associated with a temperature scale, and the indicator 16 is secured to the output shaft 17 of a conventional outdoor temperature sensing unit 13. The outdoor temperature scale is located on the front of the display panel 20 providing a continuous direct reading of the outdoor temperature. The temperature sensing unit 13 is preferably of the electronic type utilizing as the sensing element, a thermistor, but the invention is not intended to be limited to this particular type of temperature sensing means. g

In accordance with one important aspect of the present invention, the relative humidity required to maintain a predetermined condition in the ambient indoor atmosphere is automatically determined by a calculating means responsive to a manually positioned input. To this end there is provided a set hand 11, which is associated with the indoor temperature scale and mounted co-axially with the indoor temperature indicator 15; the manual positioning of set hand 11 produces an instantaneous output corresponding to the relative humidity required to maintain a predetermined condition in the indoor atmosphere. Thus, in the illustrative embodiment of FIGS. 1 and 2, the temperature sethand 11 is fixed to a cam 21 which is journalled in the lens 22, of the instrument. Cam 2] protrudes through the lens 22 and to this protrusion is fixed knob 30 by which the cam and the set-hand 11 are manually rotated.

The peripheral surface of the cam 21 acts on a tensioned filament 23, one end of which is attached to a stud 24 which is thread mounted to project inwardly from the lens 22. The other end of the filament 23 is secured to the CRH indicator 12 by means of a drum 25 which in turn is journalled in the lens 22. In this arrangement the drum and lens hole perform the function of a bearing and bearing assembly, the drum 25 is secured by means of a drum shoulder 26 and a threaded knob 28. The filament is kept under constant tension by means of a spring 29 attached to the lens 22 which acts upon the drum 25 to provide a clockwise bias to the drum. As the sethand 11 is manually rotated in respect to the indoor temperature scale, by

means ofknob 30 to correspond to the outdoor tem perature as determined by observation of the indicator midity indicator has been rotated in accordance with '16, the cam 21 which is attached to the set-hand 11 is the cam-filament calculating mechanism to indicate an optimum humidity of 30 percent which corresponds to v the relative humidity desired as indicated in the chart the filament is decreased the drum, and indicator 12,

which is fixed to the drum, rotate in a clockwise direction. As tension is increased the spring 29 is deflected causing the drum 25 and indicator 12 to dicator 12 is rotated relative to the relative humidity indica'tor scale itprovides an instantaneous indication of the relative humidity required to provide the optimum comfort condition.

A means for calibration of the tension in filament 23 is provided by the adjustable stud 24. Rotation of the stud 24 causes a displacement of the filament 23 inderotate in a counterclockwise direction.- When the iny pendent of cam 21. This displacement of the filament 1 23 through operative means. as described above to the CRH scale.

In keeping with the present invention, the cam His 7 designed so that the angular displacement thereof and the longitudinal displacement of thefilament 23in response thereto varies in accordance with the relative humidity required to maintain an optimum comfort condition for a given outdoor temperature. More particularly, the cam 21 is designed so that the angular displacement thereof causes a corresponding displacement of the comfort humidity indicator in accordance with the following chart, wherein the critical tempera-- ture is the outdoor temperature:

' For outdoor temperatures above +40F the percent CRH remains a constant 45. To ensure that a CRH in excess of is never'indicated, there is provided a CRl-l indicator stop '33 which is mounted in the lens 22 and acts to prevent the CRH" indicator 12 from ever rotating past the position which provides a'CRl-l indication of 45.

The set-hand temperature dial calibration and the relative humidity dial calibration are designed 'to produce results in accordance with the functions outlined in the preceding table, however, it must be noted I thatthe design of the invention is not limited to particular angular relationships or displacements. Moreover the calculating mechanism is not limited to any particular function or relationship, but may be designed to employ any temperature humidity relationship.

An illustration of how the invention operates may be seen by referring to FIG. 1. The outdoor temperature is indicated as being +10F (16). The set-hand 11 is positioned-to correspond with that indicated outdoor temperature of +10F. The required comfort relative hufor an outdoor temperature of +l0F. Another aspect of the invention is that the descr'epancy between I desired and ambient relative humidities may quickly be ascertained by observing the .angular displacementbetween the co-axially mounted indicators 12 and 18 in this. instance a deficiency of 15 percent in the relative humidity exists; I

From this description it may be ascertained the invention embodies very few moving parts, consequently the invention may be reliably reproduced at a high production rate with attendant low costs.

We claim as'our invention:

1. A weather instrument comprising the combination of an outdoor sensing and indicating means forproducing a continuous indication of the outdoor temperature, ambient-relative humidity sensing and indicating means for producingla continuous indication of the relative humidity of the ambient indoor atmosphere, and nonlinear means responsive to a manual positioningin accordance with said outdoor temperature for transposing .saidoutdoor temperature to a preselected indoor comfort relative humidity on said means for indicatingfsaid relative humidity said ambient relative humidity indicating means being operatively associated with said output indicating said'comfort relative humidity for producing an instantaneous indication of the differential between said comfort relative humidity and the ambient relative humidity. V

2. A weather instrument'asse't forth in'claim' 1 which includes a manually operable knob rotatably mounted on the front of the instrument, an indicating means operatively connected to said knob'and associated with an indoor temperature scale to permit manual setting of said indicating m'eansto a temperature value corresponding to theindicated outdoor temperature, and said transposition means including cam means responsive to rotation of said manually operable knob for which produces a continuous indication of the ambient.

indoor atmosphere, said ambient andcomfort indicating means being operatively associated to producean indication of the differential between said comfort relative humidity and the ambient relative humidity.

4. A weather instrument as set forth in claim 2 wherein'said indication of comfort relative humidity 1 produced by said calculating means and an ambientrelative humidity sensing and indicating means producing'a continuous indication of the ambient indoor atmosphere are operatively associated toprovide an instantarieous' indication of the differential between saidcomfort relative humidity and said ambient indoor relative humidity. 3

I 5. A weather-instrument comprising the combination of first sensing means responsive to changes in ambient outdoor temperature for producing a first continuous output corresponding to the ambient outdoor temperature, calculating means responsive to manual positioning in accordance with the indicated ambient outdoor temperature for producing an'instantaneous indication corresponding to a preselected comfort relative hu-' stantaneous indication of the differential between said required comfort relative humidity and said ambient indoor relative humidity.

7.' A weather instrument comprising the combinationof first sensing means responsive'to changes in outdoor .mosphere are operatively associated to provide an intemperatures for producing a-first continuous output corresponding to the ambient outdoor temperature, calculating means responsive to manual positioning in accordance with the indicated ambient outdoor temperatures for producing an instantaneous indication corresponding to a preselected indoorcomfort relative humidity, wherein the required comfort relative humidity is indicated as a decimal fraction which varies ina relationship to the ambient outdoor temperature in accordance with the'following table:

Outdoor Temperature Comfort Relative F Humidity --20 -10 a I -0 +l0 +20 +30 +40 all temperatures above +40 45 

1. A weather instrument comprising the combination of an outdoor sensing and indicating means for producing a continuous indication of the outdoor temperature, ambient relative humidity sensing and indicating means for producing a continuous indication of the relative humidity of the ambient indoor atmosphere, and nonlinear means responsive to a manual positioning in accordance with said outdoor temperature for transposing said outdoor temperature to a preselected indoor comfort relative humidity on said means for indicating said relative humidity, said ambient relative humidity indicating means being operatively associated with said output indicating said comfort relative humidity for producing an instantaneous indication of the differential between said comfort relative humidity and the ambient relative humidity.
 2. A weather instrument as set forth in claim 1 which includes a manually operable knob rotatably mounted on the front of the instrument, an indicating means operatively connected to said knob and associated with an indoor temperature scale to permit manual setting of said indicating means to a temperature value corresponding to the indicated outdoor temperature, and said transposition means including cam means responsive to rotation of said manually operable knob for producing said output indicating a preselected indoor comfort relative humidity.
 3. A weather instrument as set forth in claim 2 which includes a comfort relative humidity indicating means operatively connected to said cam means, and an ambient relative humidity sensing and indicating means which produces a continuous indication of the ambient indoor atmosphere, said ambient and comfort indicating means being operatively associated to produce an indication of the differential between said comfort relative humidity and the ambient relative humidity.
 4. A weather instrument as set forth in claim 2 wherein said indication of comfort relative humidity produced by said calculating means and an ambient relative humidity sensing and indicating means producing a continuous indication of the ambient indoor atmosphere are operatively associated to provide an instantaneous indication of the differential between said comfort relative humidity and said ambient indoor relative humidity.
 5. A weather instrument comprising the combination of first sensing means responsive to changes in ambient outdoor temperature for producing a first continuous output corresponding to the ambient outdoor temperature, calculating means responsive to manual positioning in accordance with the indicated ambient outdoor temperature for producing an instantaneous indication corresponding to a preselected comfort relative humidity, wherein the comfort relative humidity is indicated as a decimal fraction which varies between 15 percent and 45 percent in a direct linear relationship to ambient outdoor temperatures in the temperature range of -20*F. to +40*F, and remains constant at 45% for outdoor temperatures greater than +40*F.
 6. A weather instrument as set forth in claim 5 wherein said indication of comfort relative humidity produced by said calculating means and ambient relative humidity sensing and indicating means producing a continuous indication of the ambient indoor atmosphere are operatively associated to provide an instantaneous indication of the differential between said required comfort relative humidity and said ambient indoor relative humidity.
 7. A weather instrument comprising the combination of first sensing means responsive to changes in outdoor temperatures for producing a first continuous output corresponding to the ambient outdoor temperature, calculating means responsive to manual positioning in accordance with the indicated ambient outdoor temperatures for producing an instantaneous indication corresponding to a preselected indoor comfort relative humidity, wherein the required comfort Relative humidity is indicated as a decimal fraction which varies in a relationship to the ambient outdoor temperature in accordance with the following table: Outdoor Temperature Comfort Relative *F Humidity% -20 15 -10 20 0 25 +10 30 +20 35 +30 40 +40 45 all temperatures above +40*45 